Light emitting device

ABSTRACT

A light emitting device includes: a support substrate; at least one light emitting laminate having a structure in which semiconductor layers are laminated and formed on the support substrate; a wall unit formed on the support substrate and surrounding the at least one light emitting laminate; and a wavelength conversion layer disposed above the at least one light emitting laminate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.13/889,143 filed May 7, 2013 which claims priority to Korean PatentApplication No. 10-2012-0048047 filed on May 7, 2012, in the KoreanIntellectual Property Office, the disclosures of which are incorporatedherein by reference in their entirety.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to a light emitting device.

2. Description of the Related Art

A light emitting diode (LED), a semiconductor device that convertselectrical energy into optical energy, is a type of light emittingdevice made of a compound semiconductor material which emits lighthaving a particular wavelength according to an energy band gap.

An application of light emitting devices has extended from opticalcommunications and displays (e.g., a mobile device display or a computermonitor) and planar light sources such as a backlight unit (BLU) for anLCD, to general illumination devices. Development of a light emittingdevice for illumination requires a relatively high current, highquantity of light, and uniform light emitting characteristics (e.g.,luminescence properties or emission characteristics), such that a noveldesign and manufacturing process needs to be developed in the field.

In a conventional pre-molded reflector-type light emitting devicepackage structure, a light emitting device is mounted in a package mainbody having a reflector, and a resin unit is formed within the packagemain body to protect the light emitting device. In this case, in orderto emit white light, phosphors for converting a wavelength of lightemitted from the light emitting device may be distributed within theresin unit.

SUMMARY OF THE DISCLOSURE

There is a need in the art for a light emitting device having a reducedcolor distribution.

According to an aspect of the present disclosure, there is provided alight emitting device including: a support substrate; at least one lightemitting laminate having a structure in which semiconductor layers arelaminated and formed on the support substrate; a wall unit formed on thesupport substrate and surrounding the at least one light emittinglaminate; and a wavelength conversion layer disposed above the at leastone light emitting laminate.

The wall unit may be formed to be higher than the at least one lightemitting laminate such that an upper surface of the wall unit ispositioned higher than an upper surface of the at least one lightemitting laminate.

The wall unit may be made of a metal formed through plating, and may beformed along a circumference of the at least one light emittinglaminate.

The at least one light emitting laminate may include plural lightemitting laminates, and the wall unit may be formed between mutuallyadjacent light emitting laminates such that the mutually adjacent lightemitting laminates are disposed on both sides of the wall unit, and themutually adjacent light emitting laminates may share the wall unit.

The at least one light emitting laminate may include plural lightemitting laminates, and the wall unit surrounding any one side of oneadjacent light emitting laminate may be spaced apart from a differentwall unit surrounding another adjacent light emitting laminate by acertain interval, such that the wall unit is not connected to thedifferent wall unit.

The at least one light emitting laminate may have a structure in which afirst conductivity-type semiconductor layer, a second conductivity-typesemiconductor layer, and an active layer interposed between the firstand second conductivity-type semiconductor layers, are laminated, thelight emitting device may further include an electrode pad formed on thesupport substrate and electrically connected to any one of the first andsecond conductivity-type semiconductor layers.

The electrode pad may be disposed outside of the wall unit formed alongthe circumference of the light emitting laminate to inwardly surroundthe light emitting laminate.

The electrode pad may not be covered by the wavelength conversion layer.

The wavelength conversion layer may have wavelength conversioncharacteristics adjusted to have color distribution minimized inconsideration of light emitting characteristics of a corresponding lightemitting laminate.

The wavelength conversion characteristics of the wavelength conversionlayer may be adjusted by differentiating types of phosphors or thecontent of phosphors contained therein.

The wavelength conversion layer may be fixedly attached to the wallunit.

The support substrate may be made of a material having conductivity.

The light emitting device may further include a molding part disposed inthe wall unit to cover the light emitting laminate.

According to another aspect of the present disclosure, there is provideda light emitting device including: a support substrate; a light emittinglayer formed on the support substrate; and a conductive via extendingfrom the support substrate through the light emitting layer.

Depressions and protrusions may be formed on an upper surface of thelight emitting layer.

The light emitting layer may include a first conductivity-typesemiconductor layer, a second conductivity-type semiconductor layer, andan active layer interposed between the first and secondconductivity-type semiconductor layers.

The conductive via may extend through the light emitting layer so as tobe electrically connected to one of the first and secondconductivity-type semiconductor layers, and electrically isolated fromthe active layer and the other one of the first and secondconductivity-type semiconductor layers.

A side surface of the light emitting layer may form an acute angle witha bottom surface of the light emitting layer.

A wall unit may be formed on the light emitting layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view schematically illustrating a light emittingdevice according to an exemplary embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of the light emitting device of FIG. 1;

FIG. 3 is a cross-sectional view schematically illustrating a lightemitting laminate of the light emitting device of FIG. 1;

FIG. 4 is a plan view schematically illustrating a state in which lightemitting devices of FIG. 1 are arranged on a support substrate;

FIG. 5 is a plan view schematically illustrating another state in whichlight emitting devices of FIG. 1 are arranged on a support substrate;

FIG. 6 is a view schematically illustrating singulation (or cutting) ofa light emitting device of FIG. 4;

FIG. 7 is a cross-sectional view schematically illustrating a lightemitting device according to another exemplary embodiment of the presentdisclosure;

FIGS. 8A through 8I are views schematically illustrating a sequentialprocess of a method for manufacturing the light emitting device of FIG.7 according to another exemplary embodiment of the present disclosure;

FIG. 9 is a cross-sectional view schematically illustrating a lightemitting device according to another exemplary embodiment of the presentdisclosure; and

FIGS. 10A through 10I are views schematically illustrating a sequentialprocess of a method for manufacturing the light emitting device of FIG.9 according to another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Exemplary embodiments of the present disclosure will now be described indetail with reference to the accompanying drawings.

The present disclosure may, however, be embodied in many different formsand should not be construed as being limited to the exemplaryembodiments set forth herein.

Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey examples within the scopeof the disclosure to those having ordinary skill in the art.

In the drawings, the shapes and dimensions of elements may beexaggerated for clarity, and the same reference numerals will be usedthroughout to designate the same or like components.

A light emitting device according to an exemplary embodiment of thepresent disclosure will be described with reference to FIGS. 1 through6. FIG. 1 is a perspective view schematically illustrating a lightemitting device according to an exemplary embodiment of the presentdisclosure. FIG. 2 is a cross-sectional view of the light emittingdevice of FIG. 1. FIG. 3 is a cross-sectional view schematicallyillustrating a light emitting laminate of the light emitting device ofFIG. 1. FIG. 4 is a plan view schematically illustrating a state inwhich light emitting devices of FIG. 1 are arranged on a supportsubstrate. FIG. 5 is a plan view schematically illustrating anotherstate in which light emitting devices of FIG. 1 are arranged on asupport substrate. FIG. 6 is a view schematically illustratingsingulation (or cutting) of a light emitting device of FIG. 4.

With reference to FIGS. 1 and 2, a light emitting device 10 according toan exemplary embodiment of the present disclosure may include a supportsubstrate 100, a light emitting laminate 200, a wall unit 300, and awavelength conversion layer 400.

The support substrate 100, which serves as a support (or a prop) for thelight emitting laminate 200 formed thereon, may be made of a materialincluding at least one of gold (Au) , nickel (Ni) , aluminum (Al),copper (Cu), tungsten (W), silicon (Si), selenium (Se) and galliumarsenide (GaAs). For example, the support substrate 100 may be made ofcopper (Cu) or Si—Al (a combination of Si and Al) having conductivity.In this case, the support substrate 100 may be formed using, forexample, a plating or bonding method.

The light emitting laminate 200 may have a structure in which aplurality of semiconductor layers are laminated. A plurality of lightemitting laminates may be formed on the support substrate 100. In thiscase, the plurality of light emitting laminates 200 may be spaced apartfrom one another by certain intervals in horizontal and verticaldirections so as to be arranged in a matrix form.

The light emitting laminate 200 may include a first conductivity-typesemiconductor layer 210, an active layer 220, and a secondconductivity-type semiconductor layer 230 sequentially grown on thesupport substrate 100. The first conductivity-type semiconductor layer210 may be an n-type nitride semiconductor layer and the secondconductivity-type semiconductor layer 230 may be a p-type nitridesemiconductor layer, or vice versa.

The first and second conductivity-type semiconductor layers 210 and 230may have an empirical formula of Al_(x)In_(y)Ga_((1-x-y))N (e.g., 0≦x≦1,0≦y≦1, 0≦x+y≦1) corresponding to materials such as, for example, GaN,AlGaN, InGaN, AlInGaN, and the like. The active layer 220 formed betweenthe first and second conductivity-type semiconductor layers 210 and 230emits light having a certain level of energy according to electron-holerecombination, and may have a multi-quantum well (MQW) structure inwhich quantum well layers and quantum barrier layers are alternatelylaminated. Here, the MQW structure may be, for example, an InGaN/GaNstructure.

One of the semiconductor layers of the light emitting laminate 200 maybe electrically connected to the support substrate 100 and the other maybe electrically connected to an electrode pad 241 formed on the supportsubstrate 100. In this case, an insulator may be interposed between theelectrode pad 241 and the support substrate 100 in order to electricallyinsulate the electrode pad 241 from the support substrate 100.

In detail, as illustrated in FIG. 3, a conductive contact layer 240 maybe formed on the support substrate 100 as a conductive substrate, andthe light emitting laminate 200, namely, a laminated structure includingthe first conductivity-type semiconductor layer 210, the active layer220, and the second conductivity-type semiconductor layer 230, may beformed on the conductive contact layer 240. The conductive contact layer240 may be electrically separated from the support substrate 100, and tothis end, an insulator 250 may be interposed between the conductivecontact layer 240 and the support substrate 100.

The conductive contact layer 240 may serve to reflect light emitted fromthe active layer 220 toward an upper portion of the light emittingdevice, e.g., toward the second conductivity-type semiconductor layer230, and may form an ohmic-contact with the first conductivity-typesemiconductor layer 210. In consideration of this function, theconductive contact layer 240 may include a material such as silver (Ag),nickel (Ni), aluminum (Al), rhodium (Rh), palladium (Pd), iridium (Ir),ruthenium (Ru), magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), orthe like, or a combination of such materials. In this case, although notshown in detail, the conductive contact layer 240 may have a structureincluding two or more layers to enhance reflective efficiency. Forexample, the structure may include Ni/Ag, Zn/Ag, Ni/Al, Zn/Al, Pd/Ag,Pd/Al, Ir/Ag, Ir/Au, Pt/Ag, Pt/Al, Ni/Ag/Pt, or the like. In the presentexemplary embodiment, a portion of the conductive contact layer 240 maybe exposed to the outside, and as illustrated in FIG. 3, the exposedportion may be a region in which the light emitting laminate 200 is notformed. The exposed region of the conductive contact layer 240corresponds to an electrical connection portion for applying anelectrical signal, and the electrode pad 241 may be formed thereon.Namely, the electrode pad 241 is electrically connected to theconductive contact layer 240 to apply an electrical signal to the firstconductivity-type semiconductor layer 210. The electrode pad 241 iselectrically insulated from the support substrate 100 by the insulator250 interposed between the conductive contact layer 240 and the supportsubstrate 100. In the present exemplary embodiment, the electrode pad241 is illustrated as separated from the light emitting laminate 200 andformed at a corner of the light emitting device 10 in the vicinity ofone side of the light emitting laminate 200, but the present disclosureis not limited thereto whereby the position of the electrode pad 241 maybe variably modified.

In the present exemplary embodiment, the conductive support substrate100 is electrically connected to the second conductivity-typesemiconductor layer 230, and accordingly, an electrical signal may beapplied to the second conductivity-type semiconductor layer 230 throughthe support substrate 100. For this purpose, a conductive via 110 may beused which extends from the support substrate 100 to the secondconductivity-type semiconductor layer 230 so as to be electricallyconnected thereto.

The conductive via 110 may be connected to the second conductivity-typesemiconductor layer 230 within the second conductivity-typesemiconductor layer 230. The number, shape and pitch of the conductivevia 110, and a contact area of the conductive via 110 with the secondconductivity-type semiconductor layer 230, and the like, may beappropriately adjusted in order to lower contact resistance. In thiscase, the conductive via 110 may be electrically separated from theactive layer 220, the first conductivity-type semiconductor layer 210,and the conductive contact layer 240, by the insulator 250 formedtherebetween. Any material may be employed as the insulator 250 so longas the material has electrical insulation properties. In addition, it isdesirable for the insulator 250 to absorb as little light as possible,so, for example, a silicon oxide or a silicon nitride such as SiO₂,SiO_(x)N_(y), Si_(x)N_(y), or the like, may be used as suitablematerials for the insulator 250.

As described above, in the present exemplary embodiment, the supportsubstrate 100 is connected to the second conductivity-type semiconductorlayer 230 by the conductive via 110, so that there is no need to form anadditional electrode on an upper surface of the second conductivity-typesemiconductor layer 230. Thus, the quantity of light emitted from theupper surface of the second conductivity-type semiconductor layer 230can be increased. In this case, although the light emitting region maybe reduced due to the presence of the conductive vias 110 formed atportions of the active layer 220, the effect of enhancing lightextraction efficiency that can be obtained by omitting formation of anelectrode on the upper surface of the second conductivity-typesemiconductor layer 230 can be rather great. Meanwhile, in thesemiconductor light emitting device 10, since an electrode disposed onthe upper surface of the second conductivity-type semiconductor layer230 is not necessary, the overall electrode disposition can beconsidered similar to a horizontal electrode structure, while asufficient current spreading effect can be assured by the presence ofthe conductive vias 110 formed within the second conductivity-typesemiconductor layer 230.

Meanwhile, as illustrated in FIG. 3, a lateral side of the lightemitting laminate 200 may be sloped with respect to the conductivecontact layer 240. For example, the light emitting laminate 200 may besloped upwardly from an upper surface of the conductive contact layer240. In this way, a side surface of the light emitting laminate 200 canform, e.g., an acute angle with the upper surface of the conductivecontact layer 240. Such a sloped configuration may be naturally formedthrough a process of etching the light emitting laminate 200 to exposethe conductive contact layer 240. Depressions and protrusions may beformed on an upper surface of the light emitting laminate 200, namely,on an upper surface of the second conductivity-type semiconductor layer230. Such depressions and protrusions may be formed through an etchingprocess such as laser irradiation, dry etching, wet etching, or thelike. Preferably, a depression-and-protrusion structure having anirregular size, shape, and/or period is formed by using wet etching.Through such a structure, the probability of emitting light madeincident from the active layer 220 to the outside can be increased.

The wall unit 300 may be formed on the support substrate 100 such thatit surrounds the circumference of each of the plurality of lightemitting laminates 200. The wall unit 300 is formed to be higher thanthe light emitting laminate 200, and thus, an upper surface of the wallunit 300 is positioned to be higher than that of the light emittinglaminate 200. Accordingly, light emitted from the lateral side of thelight emitting laminate 200 may be reflected by the wall unit 300,preventing light leakage from the lateral side.

The wall unit 300 may be formed by plating a metal such as silver (Ag),aluminum (Al), nickel (Ni), or the like. As the plating method, anelectroplating method or an electroless plating method may be used.Although in the present exemplary embodiment the wall unit 300 may beformed through plating, the present disclosure is not limited thereto.

As illustrated in FIG. 4, the wall unit 300 surrounding any one side ofan adjacent light emitting laminate 200 may be spaced apart from adifferent wall unit 300 surrounding a different adjacent light emittinglaminate 200 by a certain interval. Namely, the mutually adjacent wallunits 300 are not connected. In this case, as illustrated in FIG. 6, thewall units 300 are spaced apart by an interval greater than a thicknessof a dicing blade D so that the dicing blade D does not come intocontact with the wall unit 300 when cutting (or singulating) therespective light emitting laminates 200 into individual light emittingdevices.

Alternatively, as illustrated in FIG. 5, a wall unit 300 may be formedbetween mutually adjacent light emitting laminates 200. Namely, mutuallyadjacent light emitting laminates 200 may be disposed on both sides ofthe wall unit 300. Thus, the mutually adjacent light emitting laminates200 may share the wall unit 300 therebetween. When the mutually adjacentlight emitting laminates 200 are cut into individual light emittingdevices with the dicing blade D, the wall unit 300 may be separated tosurround the respective light emitting laminates 200 as shown in FIG. 4.

The wall unit 300 may be formed along the circumference of the lightemitting laminate 200, excluding the electrode pad 241, on the supportsubstrate 100. Thus, the wall unit 300 accommodates the light emittinglaminate 200 therein, while the electrode pad 241 formed on the supportsubstrate 100 is disposed outside of the wall unit 300. Namely, the wallunit 300 is only formed along the circumference of the light emittinglaminate 200, so that light emitted from the lateral side of the lightemitting laminate 200 can be wholly reflected from the wall unit 300.Also, since the wall unit 300 serves to protect the light emittinglaminate 200, electrical reliability of the device can be enhanced. Forexample, if the active layer 220 is exposed, it may act as a currentleakage path during operation of the light emitting device. In thepresent exemplary embodiment, the active layer 220 may be prevented frombeing exposed by surrounding the circumference of the light emittinglaminate 200 with the wall unit 300.

A molding part 500 may be formed to cover the light emitting laminate200 within the wall unit 300. The molding part 500 may be made of atransparent resin having electrical insulation properties, and canhermetically seal an exposed portion of the light emitting laminate 200to prevent a possibility of generating current leakage.

The molding part 500 may contain a light diffusing agent to enhancelight extraction efficiency. The light diffusing agent may include oneor more selected from the group consisting of SiO₂, TiO₂, and Al₂O₃.

A wavelength conversion layer 400 may be disposed on respective upperportions of a plurality of light emitting laminates 200. For example,the wavelength conversion layers 400 may be fixedly attached tocorresponding wall units 300 and not disposed on upper portions of theelectrode pads 241 disposed outside of the wall units 300, and thus, theelectrode pads 241 are not covered by the wavelength conversion layers400. Accordingly, without being interfered with by the wavelengthconversion layer 400, the electrode pads 241 may be bonded to wires W tobe electrically connected to an external power surface, e.g., a leadframe or the like, on which the light emitting device 10 is to bemounted.

The wavelength conversion layer 400 serves to convert a wavelength oflight emitted from the light emitting laminate 200, and to this end, astructure in which at least one kind of phosphor is dispersed in atransparent resin may be used. Light converted by the wavelengthconversion layer 400 may be mixed with light emitted from the lightemitting laminate 200 to implement white light. For example, when thelight emitting laminate 200 emits blue light, a yellow phosphor may beused; and when the light emitting laminate 200 emits ultraviolet light,red, green, and blue phosphors may be mixedly used. The colors of thephosphors and the light emitting laminate 200 may be variably combinedto emit white light. Also, wavelength conversion materials for differentcolors such as green, red, and the like, may be applied to implement alight source for emitting relevant colors (i.e., other than whitelight).

For example, when blue light is emitted from the light emitting laminate200, the red phosphor used therewith may include a MAlSiNx:Re (1≦x≦5)nitride phosphor, an MD:Re sulfide phosphor, and the like. Here, M maybe at least one selected from among Ba, Sr, Ca, and Mg, and D may be atleast one selected from among S, Se, and Te, while Re may be at leastone selected from among Eu, Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er,Tm, Yb, Lu, F, Cl, Br, and I. The green phosphor used therewith mayinclude an M₂SiO₄:Re silicate phosphor, an MA₂D₄:Re sulfide phosphor, aβ-SiAlON:Re phosphor, and an MA′₂O₄:Re′ oxide-based phosphor, and thelike. Here, M may be at least one selected from among Ba, Sr, Ca, andMg, A may be at least one selected from among Ga, Al, and In, D may beat least one selected from among S, Se, and Te, A′ may be at least oneselected from among Sc, Y, Gd, La, Lu, Al, and In, Re may be at leastone selected from among Eu, Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er,Tm, Yb, Lu, F, Cl, Br, and I, and Re′ may be at least one selected fromamong Ce, Nd, Pm, Sm, Tb, Dy, Ho, Er, Tm, Yb, F, Cl, Br, and I.

The wavelength conversion layer 400 may include quantum dots in place ofthe phosphors or provided with the phosphors. A quantum dot is anano-crystal particle including a core and a shell, and the core sizethereof ranges from 2 nm to 100 nm. By adjusting the core size, thequantum dot may be used as phosphors emitting various colors such asblue (B), yellow (Y), green (G), and red (R). At least two types ofsemiconductors among group II-VI compound semiconductors (e.g., ZnS,ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, MgTe, etc.), group III-Vcompound semiconductors (e.g., GaN, GaP, GaAs, GaSb, InN, InP, InAs,InSb, AlAs, AlP, AlSb, AlS, etc.), or a group IV semiconductor (Ge, Si,Pb, etc.) may be hetero-joined to form a core and shell structureconstituting a quantum dot. In this case, in order to terminatemolecular binding on a surface of the shell of the quantum dot at anouter edge of the shell, in order to restrain cohesion of quantum dotsto improve the dispersibility of a resin such as silicon resin, epoxyresin, or the like, or in order to improve the phosphor function, anorganic ligand, using a material such as oleic acid, may be formed. Thequantum dot is vulnerable to moisture or air, and in particular, whenthe quantum dot is in contact with a lead frame (not shown) of a packageor an electrode pattern (not shown) of the substrate of an illuminationdevice, or the like, in which the light emitting device according to thepresent disclosure is to be mounted, a chemical reaction may take place.Thus, as illustrated in the drawings, the wavelength conversion layer400 may be applied on only the upper surface of the light emittinglaminate 200, thereby eliminating the possibility of contact with theelectrode pad or the support substrate, to thus enhance reliabilitythereof. Although the phosphors are taken as an example of thewavelength conversion material, the phosphors can be replaced withquantum dots, or quantum dots may be added to the phosphors.

The wavelength conversion layer 400 may have wavelength conversioncharacteristics adjusted such that color distribution is minimized inconsideration of light emitting characteristics (e.g., luminescenceproperties or emission characteristics) of a corresponding lightemitting laminate 200. The wavelength conversion characteristics of eachwavelength conversion layer 400 may be adjusted by differentiating thetypes of phosphors or differentiating the content of the phosphorscontained in each wavelength conversion layer 400, or the like.

In this manner, by selectively using an appropriate wavelengthconversion layer 400 according to the characteristics of each lightemitting laminate 200, color distribution can be adjusted to the MacAdamvariance ellipse 3 step level.

FIG. 7 illustrates a light emitting device according to anotherexemplary embodiment of the present disclosure. Components constitutingthe light emitting device and a basic structure thereof according to theexemplary embodiment illustrated in FIG. 7 are substantially similar tothose of the exemplary embodiment illustrated in FIGS. 1 and 2, exceptfor the structure of the wall unit. Thus, descriptions of the samecomponents and structure as those of the foregoing embodiment will beomitted and a variation of the wall unit will mainly be described.

FIG. 7 is a cross-sectional view schematically illustrating a lightemitting device according to another exemplary embodiment of the presentdisclosure. Referring to FIG. 7, a light emitting device 10′ may includethe support substrate 100, the light emitting laminate 200, a wall unit300′, and the wavelength conversion layer 400.

The support substrate 100, which serves as a support (or a prop) for thelight emitting laminate 200 formed thereon, may be made of, for example,a material including at least one selected from the group consisting ofgold (Au), nickel (Ni), aluminum (Al), copper (Cu), tungsten (W),silicon (Si), selenium (Se) and gallium arsenide (GaAs). For example, asupport substrate 100 having conductivity may be made of copper (Cu) orsilicon-aluminum (Si—Al) (i.e., a combination of silicon (Si) andaluminum (Al)).

A metal layer 120 may be disposed on a lower surface of the supportsubstrate 100 and electrically connected to the support substrate 100.

The light emitting laminate 200, having a structure in which a pluralityof semiconductor layers are laminated, may be formed on the supportsubstrate 100. An exemplary structure and configuration of the lightemitting laminate 200 are illustrated and described in detail in FIG. 3and the corresponding description therefor, so detailed descriptionsthereof will be omitted here.

In FIG. 7, a single light emitting laminate 200 provided on the supportsubstrate 100 is illustrated, but the present disclosure is not limitedthereto. For example, a plurality of light emitting laminates 200 may beprovided, and in this case, the plurality of light emitting laminates200 may be spaced apart from one another at certain intervals inhorizontal and/or vertical directions so as to be arranged in a matrix.

The wall unit 300′ may be formed on sloped lateral surfaces of the lightemitting laminate 200 such that the wall unit 300′ surrounds thecircumference of a corresponding light emitting laminate 200. Thus, whenthe light emitting laminate 200 is viewed from above, unlike theexemplary embodiment illustrated in FIG. 2 in which the upper surfaceand the sloped lateral surfaces of the light emitting laminate 200 arevisible, in the present embodiment, only the upper surface of the lightemitting laminate 200 is visible while the sloped lateral surfaces arecovered by the wall unit 300′so as to be invisible, and only an uppersurface of the wall unit 300′ is visible.

The wall unit 300′ is formed to extend higher than the light emittinglaminate 200, so that the upper surface of the wall unit 300′ ispositioned higher than that of the light emitting laminate 200.Accordingly, light emitted from a lateral side of the light emittinglaminate 200 may be reflected by the wall unit 300′, thereby preventinglight leakage from the lateral side.

The wall unit 300′ may be made of a resin in which at least one type ofphosphor is dispersed. Also, the wall unit 300′ may have a structure inwhich a powder, formed of a material such as TiO₂, Ag, or the like, isdispersed instead of phosphors.

Meanwhile, the wall unit 300′ is formed on the lateral surfaces of thelight emitting laminate 200 and surrounds the circumference of the lightemitting laminate 200, so that the electrode pad 241 formed on thesupport substrate 100 may be disposed outside of the wall unit 300′,similarly to the exemplary embodiment illustrated in FIGS. 1 and 2.

However, in the embodiment of FIG. 2, the wall unit 300 is formed on thesupport substrate 100 and spaced apart from the light emitting laminate200 by a predetermined interval. By comparison, in the presentembodiment, the wall unit 300′ may be in direct contact with the lateralsurfaces of the light emitting laminate 200, effecting a structure moreappropriate for a smaller light emitting device.

The wavelength conversion layer 400 may be fixedly attached to the wallunit 300′ such that the wavelength conversion layer 400 covers the lightemitting laminate 200. When the light emitting device 10′ is viewed fromabove, the wavelength conversion layer 400 may have a shapecorresponding to the light emitting laminate 200. Since the wavelengthconversion layer 400 is not disposed on an upper portion of theelectrode pad 241 disposed outside of the wall unit 300′, the electrodepad 241 is not covered by the wavelength conversion layer 400. Thus,without being interfered with by the wavelength conversion layer 400,the electrode pad 241 may be bonded to a wire W so as to be electricallyconnected to an external power source, e.g., a lead frame or the like,on which the light emitting device 10′ is to be mounted.

A configuration of the wavelength conversion layer 400 in the presentembodiment may be substantially similar to that of the exemplaryembodiment illustrated in FIG. 1, so that a detailed description thereofwill be omitted.

A method for manufacturing a light emitting device according to thepresent embodiment will be described with reference to FIGS. 8A through8I. FIGS. 8A through 8I are views schematically illustrating asequential process of a method for manufacturing the light emittingdevice of FIG. 7 according to another exemplary embodiment of thepresent disclosure.

First, as illustrated in FIG. 8A, a support substrate 100 with the lightemitting laminate 200 formed on one surface thereof is prepared. Aplurality of light emitting laminates 200 may be spaced apart from oneanother at certain intervals in horizontal and/or vertical directions soas to be arranged in a matrix on the support substrate 100.

The support substrate 100 may be made of silicon-aluminum (Si—Al) (i.e.,a combination of silicon (Si) and aluminum (Al)) so as to haveconductivity. A conductive contact layer 240 may be formed on thesupport substrate 100.

A portion of the conductive contact layer 240 may be exposed to theoutside, and the electrode pad 241 for applying an electrical signal maybe formed on the exposed portion of the conductive contact layer 240.The conductive contact layer 240 is electrically separated from thesupport substrate 100 by an insulator 250 which may be interposedbetween the conductive contact layer 240 and the support substrate 100.

The light emitting laminate 200 may have a structure in which aplurality of semiconductor layers are laminated. The light emittinglaminate 200 may include the first conductivity-type semiconductor layer210, the active layer 220, and the second conductivity-typesemiconductor layer 230.

The conductive support substrate 100 may be electrically connected tothe second conductivity-type semiconductor layer 230 through theconductive via 110 penetrating the active layer 220, the firstconductivity-type semiconductor layer 210, and the conductive contactlayer 240. Accordingly, an electrical signal may be applied to thesecond conductivity-type semiconductor layer 230 through the supportsubstrate 100. In this case, the insulator 250 may be formed between theconductive via 110 and the active layer 220, the first conductivity-typesemiconductor layer 210, and the conductive contact layer 240.

An exemplary structure of the light emitting laminate 200 and thesupport substrate 100 is substantially similar to that illustrated inFIG. 3, so that a detailed description thereof will be omitted.

As shown in FIG. 8A, photoresist patterns 600 are formed on the supportsubstrate 100 such that the photoresist patterns 600 cover uppersurfaces of the electrode pads 241 and light emitting laminates 200.

The photoresist patterns 600 may be formed to partially cover uppersurfaces of the light emitting laminates 200 and upper surfaces of thesubstrate 100, such that the sloped lateral surfaces of the lightemitting laminates 200 are not covered. In this case, spaces 601 betweenthe photoresist patterns 600, in which the sloped lateral surfaces ofthe light emitting laminates 200 are exposed, may have a shapecorresponding to the wall unit 300′. Thus, the photoresist patterns 600may serve as a type of mold.

The photoresist patterns 600 may be formed through a method such asscreen printing, or the like.

Thereafter, as illustrated in FIG. 8B, a resin R is dispensed on thesupport substrate 100 having the light emitting laminates 200 formedthereon. The resin R entirely covers the upper surface of the supportsubstrate 100 including the photoresist patterns 600 and the lightemitting laminates 200 such that the resin R fills the spaces 601between the photoresist patterns 600. Accordingly, the sloped lateralsurfaces of the light emitting laminate 200 are covered by the resin R.The resin R may be cured through an additional process.

At least one type of phosphor may be contained in the resin R in adispersed manner. Also, the resin R may contain TiO₂, Ag powder, or thelike.

Thereafter, as illustrated in FIG. 8C, planarization is performed byremoving portions of the cured resin R and the photoresist patterns 600to obtain an overall flat and even upper surface.

Thereafter, as illustrated in FIG. 8D, the photoresist patterns 600 areremoved to form the wall units 300′ on the sloped lateral surfaces ofthe light emitting laminate 200. The wall units 300′ are formed bycuring the resin R filling the spaces 601 between the photoresistpatterns 600, and when the photoresist patterns 600 are removed, thewall units 300′ protruding from the side walls may be exposed.

Thereafter, as illustrated in FIG. 8E, a portion of the supportsubstrate 100 is ground from an opposite surface so as to be partiallyremoved, and the metal layer 120 is formed on the resulting oppositesurface of the support substrate 100 as illustrated in FIG. 8F. Themetal layer 120 may apply an electrical signal, like the electrode pad241 formed on the support substrate 100. The metal layer 120 maycorrespond to a different type of electrode pad having a polaritydifferent from that of the electrode pad 241.

Thereafter, as illustrated in FIG. 8G, the respective light emittinglaminates 200 are singulated (or cut) into individual light emittingdevices through a dicing process. Thereafter, as illustrated in FIG. 8H,power is applied to the respective light emitting devices to measurelight emitting characteristics (e.g., luminescence properties oremission characteristics) thereof. The light emitting devices are thensorted according to the measured light emitting characteristics.

Thereafter, as illustrated in FIG. 8I, the wavelength conversion layer400 is attached to the light emitting device to complete the lightemitting device 10′. The wavelength conversion layers 400 may be fixedlyattached to the wall units 300′ of the respective light emittinglaminates 200 and not disposed on upper portions of the electrode pads241 disposed outside of the wall units 300′, and thus, the electrodepads 241 are not covered by the wavelength conversion layers 400.

As the wavelength conversion layer 400, a wavelength conversion layerhaving wavelength conversion characteristics adjusted such that colordistribution is minimized in consideration of the light emittingcharacteristics of the corresponding light emitting devices,specifically, the respective light emitting laminates 200, may beemployed. The wavelength conversion characteristics of each wavelengthconversion layer 400 may be adjusted by differentiating the types ofphosphors contained in each wavelength conversion layer 400, bydifferentiating the amount of phosphors contained in each wavelengthconversion layer 400, by differentiating a thickness of each wavelengthconversion layer 400, or the like. Thus, color distribution of thecompleted light emitting devices can be adjusted to the MacAdam varianceellipse 3 step level.

FIG. 9 is a cross-sectional view schematically illustrating a lightemitting device according to another exemplary embodiment of the presentdisclosure. Components constituting the light emitting device and abasic structure thereof according to the exemplary embodimentillustrated in FIG. 9 are substantially similar to those of theexemplary embodiment illustrated in FIG. 7, except for the structure ofthe wall unit. Thus, descriptions of the same components and structureas those of the foregoing embodiment will be omitted and a variation ofthe wall unit will be mainly described.

FIG. 9 is a cross-sectional view schematically illustrating a lightemitting device according to another exemplary embodiment of the presentdisclosure. Referring to FIG. 9, the light emitting device may includethe support substrate 100, the light emitting laminate 200, a moldingpart 500′, and the wavelength conversion layer 400.

The support substrate 100, which serves as a support (or a prop) for thelight emitting laminate 200 formed thereon, may be made of, for example,copper (Cu) or silicon-aluminum (Si—Al) (i.e., a combination of silicon(Si) and aluminum (Al)) having conductivity. The metal layer 120 may bedisposed on a lower surface of the support substrate 100 andelectrically connected to the support substrate 100.

The light emitting laminate 200, having a structure in which a pluralityof semiconductor layers are laminated, may be formed on the supportsubstrate 100. An exemplary structure and configuration of the lightemitting laminate 200 are illustrated and described in detail in FIG. 3and the corresponding description therefor, so detailed descriptionsthereof will be omitted here.

The molding part 500′ may be formed on the sloped lateral surfaces andupper surface of the light emitting laminate 200 so as to encapsulatethe light emitting laminate 200. Thus, when the light emitting laminate200 is viewed from above, unlike the exemplary embodiment illustrated inFIG. 2 in which the upper surface and the sloped lateral surfaces of thelight emitting laminate 200 are visible and unlike the exemplaryembodiment illustrated in FIG. 7 in which only the upper surface of thelight emitting laminate 200 is visible, in the present embodiment, thesurface of the light emitting laminate 200 is covered by the moldingpart 500′ so as to be invisible, and only an upper surface of themolding part 500′ may be visible. Accordingly, light emitted from thelateral side of the light emitting laminate 200 may be reflected by themolding part 500′, thereby preventing light leakage from the lateralside.

Like the wall unit 300′, the molding part 500′ may be made of a resin inwhich at least one type of phosphor is dispersed. Also, the molding part500′ may have a structure in which a powder, formed of a material suchas TiO₂, Ag, or the like, is dispersed instead of phosphors.

Meanwhile, the molding part 500′ surrounds the circumference of thelight emitting laminate 200 so that similar to the embodimentsillustrated in FIGS. 2 and 7, the electrode pad 241 formed on thesupport substrate 100 may be disposed outside the molding part 500′,rather than being covered by the molding part 500′.

Also, in comparison to the embodiment of FIG. 7 in which the wall unit300′ covers only the lateral surfaces of the light emitting laminate200, in the present embodiment, the molding part 500′ covers both theupper surface of the light emitting laminate 200 and the lateralsurfaces of the light emitting laminate 200. However, the overallstructures of both embodiments are substantially similar, and like theembodiment of FIG. 7, advantageously, the light emitting deviceaccording to the present embodiment can be reduced in size.

The wavelength conversion layer 400 may be fixedly attached to themolding part 500′ such that the wavelength conversion layer 400 coversthe light emitting laminate 200. When the light emitting device 10″ isviewed from above, the wavelength conversion layer 400 may have a shapecorresponding to the light emitting laminate 200. Since the wavelengthconversion layer 400 is not disposed on an upper portion of theelectrode pad 241 disposed outside of the molding part 500′, theelectrode pad 241 is not covered by the wavelength conversion layer 400.Thus, without being interfered with by the wavelength conversion layer400, the electrode pad 241 may be bonded to a wire W so as to beelectrically connected to an external power source, e.g., a lead frameor the like, on which the light emitting device 10″ is to be mounted.

A configuration of the wavelength conversion layer 400 in the presentembodiment may be substantially similar to that of the exemplaryembodiment illustrated in FIG. 1, so that a detailed description thereofwill be omitted.

A method for manufacturing a light emitting device according to thepresent embodiment will be described with reference to FIGS. 10A through10I. FIGS. 10A through 10I are views schematically illustrating asequential process of a method for manufacturing the light emittingdevice of FIG. 9 according to another exemplary embodiment of thepresent disclosure.

First, as illustrated in FIG. 10A, a support substrate 100 with thelight emitting laminate 200 formed on one surface thereof is prepared. Aplurality of light emitting laminates 200 may be spaced apart from oneanother in horizontal and/or vertical directions with a certain intervaltherebetween, so as to be arranged on the support substrate 100 in amatrix.

An exemplary structure of the light emitting laminate 200 and thesupport substrate 100 is substantially similar to those illustrated inFIGS. 3 and 7, so that a detailed description thereof will be omittedhere.

As shown in FIG. 10A, photoresist patterns 600 are formed on the supportsubstrate 100 such that the photoresist patterns 600 cover uppersurfaces of the electrode pads 241. The photoresist patterns 600 may beformed to partially cover the upper surface of the support substrate100, such that the sloped lateral surfaces and the upper surfaces of thelight emitting laminates 200 are not covered. Namely, unlike theembodiment of FIG. 7 in which the photoresist patterns 600 are formed onthe upper surfaces of the light emitting laminate 200, in the presentembodiment, the photoresist patterns 600 are not formed on the uppersurfaces of the light emitting laminates 200.

Thereafter, as illustrated in FIG. 10B, a resin R is dispensed on thesupport substrate 100 having the light emitting laminates 200 formedthereon. to the resin R entirely covers the upper surface of the supportsubstrate 100 including the photoresist patterns 600 and the lightemitting laminates 200 such that the resin R fills the spaces betweenthe photoresist patterns 600. Accordingly, the sloped lateral surfacesand the upper surfaces of the light emitting laminate 200 are covered bythe resin R. The resin R may be cured through an additional process.

At least one type of phosphor may be contained in the resin R in adispersed manner. Also, the resin R may contain TiO₂, Ag powder, or thelike.

Thereafter, as illustrated in FIG. 10C, planarization is performed byremoving portions of the cured resin R and the photoresist pattern 600to obtain an overall flat and even upper surface.

Thereafter, as illustrated in FIG. 10D, the photoresist patterns 600 areremoved to form the molding parts 500′ encapsulating the sloped lateralsurfaces and upper surfaces of the light emitting laminates 200. Themolding parts 500′ are formed by curing the resin R filling the spacesbetween the photoresist patterns 600, and when the photoresist patterns600 are removed, the molding parts 500′ encapsulating the lateral andupper surfaces of the light emitting laminates 200 may be exposed.

Thereafter, as illustrated in FIG. 10E, a portion of the supportsubstrate 100 is ground from an opposite surface so as to be partiallyremoved, and the metal layer 120 is formed on the resulting oppositesurface of the support substrate 100 as illustrated in FIG. 10F. Themetal layer 120 may apply an electrical signal, like the electrode pad241 formed on the support substrate 100. The metal layer 120 maycorrespond to a different type of electrode pad having a polaritydifferent from that of the electrode pad 241.

Thereafter, as illustrated in FIG. 10G, the respective light emittinglaminates 200 are singulated (or cut) into individual light emittingdevices through a dicing process. Thereafter, as illustrated in FIG.10H, power is applied to the respective light emitting devices tomeasure light emitting characteristics (e.g., luminescence properties oremission characteristics) thereof. The light emitting devices are thensorted according to the measured light emitting characteristics.

Thereafter, as illustrated in FIG. 10I, the wavelength conversion layer400 is attached to the light emitting device to complete the lightemitting device 10″. The wavelength conversion layers 400 may be fixedlyattached to the molding parts 500′ of the respective light emittinglaminates 200 and not disposed on upper portions of the electrode pads241 disposed outside of the molding parts 500′, and thus, the electrodepads 241 are not covered by the wavelength conversion layers 400.

As the wavelength conversion layer 400, a wavelength conversion layerhaving wavelength conversion characteristics adjusted such that colordistribution is minimized in consideration of the light emittingcharacteristics of the corresponding light emitting devices,specifically, the respective light emitting laminates 200, may beemployed. The wavelength conversion characteristics of each wavelengthconversion layer 400 may be adjusted by differentiating the types ofphosphors contained in each wavelength conversion layer 400, bydifferentiating the amount of phosphors contained in each wavelengthconversion layer 400, by differentiating a thickness of each wavelengthconversion layer 400, or the like. Thus, color distribution of thecompleted light emitting devices can be adjusted to the MacAdam varianceellipse 3 step level.

The light emitting device manufactured thusly may be used as a lightsource of a lighting device such as, for example, an MR16 lamp, avehicle head lamp, or the like.

As set forth above, according to exemplary embodiments of the presentdisclosure, a light emitting device can be provided in which generationof a lateral light leakage can be prevented even if the wavelengthconversion layer for converting a wavelength of light is provided abovethe light emitting device, and color distribution can be reduced byadjusting wavelength conversion characteristics in consideration oflight characteristics of the light emitting device.

Various features and advantages of the present disclosure are notlimited to the foregoing content and may be easily understood in theprocess of describing detailed embodiments of the present disclosure.

While the present disclosure has been shown and described in connectionwith the exemplary embodiments, it will be apparent to those havingordinary skill in the art that modifications and variations can be madewithout departing from the spirit and scope of the present disclosure asdefined by the appended claims.

What is claimed is:
 1. A light emitting device comprising: at least onelight emitting laminate having a structure in which a firstconductivity-type semiconductor layer, a second conductivity-typesemiconductor layer, and an active layer interposed between the firstand second conductivity-type semiconductor layers, are laminated; a wallunit surrounding the at least one light emitting laminate; a wavelengthconversion layer disposed above the at least one light emittinglaminate; and a conductive via extending through the at least one lightemitting laminate so as to be electrically connected to one of the firstand second conductivity-type semiconductor layers, and electricallyisolated from the active layer and the other one of the first and secondconductivity-type semiconductor layers.
 2. The light emitting device ofclaim 1, wherein depressions and protrusions are formed on an uppersurface of the light emitting laminate.
 3. The light emitting device ofclaim 1, wherein the first and second conductivity-type semiconductorlayers are at least one of GaN, AlGaN, InGaN and AlInGaN, and the activelayer has a multi-quantum well (MQW) structure in which quantum welllayers and quantum barrier layers are an InGaN/GaN structure.
 4. Thelight emitting device of claim 1, wherein a conductive contact layer isformed to reflect light emitted from the active layer toward an upperportion of the light emitting device, and forms an ohmic-contact withthe first conductivity-type semiconductor layer.
 5. The light emittingdevice of claim 4, wherein the conductive contact layer includes one ormore materials selected from the group consisting of silver (Ag), nickel(Ni), aluminum (Al), rhodium (Rh), palladium (Pd), iridium (Ir),ruthenium (Ru), magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), ora combination of such materials.
 6. The light emitting device of claim4, wherein an electrode pad is electrically connected to the conductivecontact layer and applies an electrical signal to the firstconductivity-type semiconductor layer.
 7. The light emitting device ofclaim 4, wherein a side surface of the light emitting layer is slopedwith respect to the conductive contact layer.
 8. The light emittingdevice of claim 1, wherein the wall unit is configured to reflect lightemitted from lateral sides of the light emitting laminate.
 9. The lightemitting device of claim 1, wherein a molding part is formed to coverthe light emitting laminate within the wall unit.
 10. The light emittingdevice of claim 9, wherein the molding part contains a light diffusingagent, the light diffusing agent includes one or more selected from thegroup consisting of SiO₂, TiO₂, and Al₂O₃.
 11. The light emitting deviceof claim 1, wherein the light emitting laminate emits ultraviolet light.12. The light emitting device of claim 11, wherein red, green, and bluephosphors are mixedly used.
 13. The light emitting device of claim 1,wherein the wavelength conversion layer includes at least one of aMAlSiNx:Re (1≦x≦5) nitride phosphor, an MD:Re sulfide phosphor, whereinM is at least one selected from among Ba, Sr, Ca, and Mg, and D is atleast one selected from among S, Se, and Te, while Re is at least oneselected from among Eu, Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm,Yb, Lu, F, Cl, Br, and I.
 14. The light emitting device of claim 1,wherein the wavelength conversion layer includes at least one of anM₂SiO₄:Re silicate phosphor, an MA₂D₄:Re sulfide phosphor, a β-SiAlON:Rephosphor, and an MA′₂O₄:Re′ oxide-based phosphor, wherein M is at leastone selected from among Ba, Sr, Ca, and Mg, A is at least one selectedfrom among Ga, Al, and In, D is at least one selected from among S, Se,and Te, A′ is at least one selected from among Sc, Y, Gd, La, Lu, Al,and In, Re is at least one selected from among Eu, Y, La, Ce, Nd, Pm,Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl, Br, and I, and Re′ is atleast one selected from among Ce, Nd, Pm, Sm, Tb, Dy, Ho, Er, Tm, Yb, F,Cl, Br, and I.
 15. The light emitting device of claim 1, wherein thewavelength conversion layer includes quantum dots.
 16. The lightemitting device of claim 15, wherein the quantum dot is a hetero-joinedcore and shell structure.
 17. The light emitting device of claim 16,wherein the core size ranges from 2 nm to 100 nm.
 18. The light emittingdevice of claim 15, wherein the quantum dot includes one or moresemiconductors selected from the group consisting of group II-VIcompound semiconductors, group III-V compound semiconductors, and groupIV semiconductor.
 19. The light emitting device of claim 1, wherein acolor distribution of the wavelength conversion layer is adjusted to theMacAdam variance ellipse 3 step level.
 20. The light emitting device ofclaim 1, wherein the wall unit has a structure in which at least one ofTiO₂ and Ag is dispersed.